Year	Number
1994	25.27448
1995	26.79364
1996	26.56025
1997	23.85478
1998	22.48337
1999	21.83443
2000	21.46774
2001	20.96118
2002	20.66405
2003	19.8657
2004	20.29486
2005	20.71698
2006	20.71353
2007	20.46054
2008	20.10489
2009	19.77198
2010	19.27869
2011	18.05587
2012	17.33298
2013	16.78315
2014	15.81338
2015	15.08387
2016	14.16721
2017	13.55685